Module 15.5 Combustion Section

Question 1

What are the two combustion chamber cooling methods?

Answer 1

• Transpiration
• Film

Question 2

What are the 3 types of combustion chamber?

Answer 2

• Can-type
• Can-annular
• Annular

Question 3

What are the requirements for a combustion chamber?

Answer 3

• Safe ignition
• Stable combustion
• Complete combustion
• Equal temperature distribution
• Min pressure loss

Question 4

The combustion chamber should be?

Answer 4

• Small and light
• Dependable cooling
• High operating lifetime

Question 5

What is the optimum air fuel ratio?

Answer 5

15:1

Question 6

What is the percentage of secondary airflow?

Answer 6

70-80%

Question 7

What is inside the casing?

Answer 7

Flame tube

Question 8

What is the function of the flame tube?

Answer 8

Control and guide the flame

Question 9

What cools the flame tube?

Answer 9

Secondary airflow

Question 10

what sprays the fuel into the centre of the airflow?

Answer 10

Fuel nozzle/injectors

Question 11

Air is slowed before entering the combustion chamber to ensure what?

Answer 11

Complete combustion

Question 12

What is the percentage of primary flow?

Answer 12

20-30%

Question 13

What is the primary airflow used for?

Answer 13

The combustion process

Question 14

What causes the vaporised fuel that is mixed with the air to combust?

Answer 14

Igniter plug

Question 15

Where does secondary air flow into the flame tube?

Answer 15

Dilution/mixer zone

Question 16

What are the advantages of can-type chambers?

Answer 16

• Simple design
• Good structural strength
• Removed and replaced individually

Question 17

What is the difference between can-type and can-annular?

Answer 17

Can-annular, all of flame tubes share the same case

Question 18

What are the 3 major parts of an annular combustion chamber?

Answer 18

• Dome
• Inner liner
• Outer liner

Question 19

How many flame tubes are in an annular combustion chamber?

Answer 19

One

Question 20

What does the dome house?

Answer 20

Fuel nozzle and swirl vanes

Question 21

What is the special design for APU and Small GTE called?

Answer 21

Reverse flow

Question 22

What are the 3 sections of an annular combustion chamber?

Answer 22

• Case
• Flame tube
• External components fitted to outer wall

Question 23

What are the 3 parts of a combustion case?

Answer 23

• Outer wall
• Inner wall
• Diffuser

Question 24

What prevents air leaks in front of the inner wall flange?

Answer 24

Compressor Discharge Pressure (CDP) Seal

Question 25

What are the vanes known as at the end of the HP compressor?

Answer 25

Exit guide vanes

Question 26

How many igniters are found in an annular chamber?

Answer 26

Two

Question 27

What does the flame tube dome section connect?

Answer 27

The inner and outer liner

Question 28

What method of cooling is between the inner surface of the liners?

Answer 28

Film cooling

Question 29

Where does the air go in transpiration cooling?

Answer 29

Enters the flame tube by radial holes in the liner

Question 30

What is a method of reducing emissions?

Answer 30

Dual dome